The present invention relates to a xcex2-diketonatocopper(I) complex useful in forming a thin copper film by metal-organic vapor deposition (hereinafter abbreviated as MOCVD) method and a process for producing the same.
Conventionally, as a raw material for forming a thin copper film by MOCVD method, is well known xcex2-diketonatocopper(I) complex comprising (vinyltrimethylsilane) (1,1,1,5,5,5-hexafluoro-2,4-pentanedionato) copper(I) of formula (xcex1) 
disclosed in Japanese Patent Laid-open No. Hei 5-59551.
However, vinyltrimethylsilane is used as a ligand for the xcex2-diketonatocopper(I) complex of the formula (xcex1). Conventionally, xcex2-diketonatocopper(I) complex in which an allene compound is used as a ligand has not been known.
The present inventors research hard to find out novel xcex2-diketonatocopper(I) complex in which an allene compound is used as a ligand from the above-mentioned viewpoint, and come to obtain xcex2-diketonatocopper(I) complexes of formula (2) described below in which an allene compound of formula (1) described below is used as a ligand.
That is, the present invention relates to a xcex2-diketonatocopper(I) complex which contains as a ligand (L) an allene compound of formula (1) 
wherein R1, R2, R3 and R4 may be the same or different and each represents hydrogen, C1-4 alkyl or (R5)3Sixe2x80x94, or R1 and R2, together with the carbon atom bonding them, may form 3- to 6-member ring, or R2 and R3, together with the allene bond group bonding them, may form 8- to 10-member ring, R5s may be the same or different and independently of one another represent linear or branched C1-4 alkyl, and which is represented by formula (2) 
wherein, R6 and R7 may be the same or different and each represents linear or branched C1-4 alkyl, C1-4 alkoxy, or linear or branched C1-4 fluoroalkyl, R8 represents hydrogen or fluorine, and L represents the allene compound of formula (1).
Then, the present invention will be concretely explained.
The following is exemplified for each of the substituents in the chemical structural formula of allene compounds represented by formula (1) that is the ligand in the xcex2-diketonatocopper(I) complexes of formula (2).
The substituents R1, R2, R3 and R4include, for example H, Me, Et, n-Pr, n-Bu, i-Pr, i-Bu, s-Bu, t-Bu, Me3Si, Et3Si, n-Pr3Si, n-Bu3Si, i-Pr3Si, i-Bu3Si, s-Bu3Si, t-Bu3Si, Me2(Et)Si, Me2(n-Pr)Si, Me2(n-Bu)Si, Me2(i-Pr)Si, Me2(i-Bu)Si, Me2(s-Bu)Si, Me2(t-Bu)Si, Et2(Me)Si, Et2(n-Pr)Si, Et2(n-Bu)Si, Et2(i-Pr)Si, Et2(i-Bu)Si, Et2(s-Bu)Si, Et2(t-Bu)Si, n-Pr2(Me)Si, n-Pr2(Et)Si, n-Pr2(i-Pr)Si, n-Pr2(n-Bu)Si, n-Pr2(s-Bu)Si, n-Pr2(t-Bu)Si, n-Bu2(Me)Si, n-Bu2(Et)Si, n-Bu2(n-Pr)Si, n-Bu2(i-Pr)Si, n-Bu2(i-Bu)Si, n-Bu2(s-Bu)Si, n-Bu2(t-Bu)Si, i-Pr2(Me)Si, i-Pr2(Et)Si, i-Pr2(n-Pr)Si, i-Pr2(n-Bu)Si, i-Pr2(s-Bu)Si, i-Pr2(t-Bu)Si, i-Bu2(Me)Si, i-Bu2(Et)Si, i-Bu2(n-Pr)Si, i-Bu2(n-Bu)Si, i-Bu2(i-Pr)Si, i-Bu2(s-Bu)Si, i-Bu2(t-Bu)Si, s-Bu2(Me)Si, s-Bu2(Et)Si, s-Bu2(n-Pr)Si, s-Bu2(n-Bu)Si, s-Bu2(i-Pr)Si, s-Bu2(i-Bu)Si, s-Bu2(t-Bu)Si, t-Bu2(Me)Si, t-Bu2(Et)Si, t-Bu2(n-Pr)Si, t-Bu2(n-Bu)Si, t-Bu2(i-Pr)Si, t-Bu2(i-Bu)Si or t-Bu2(s-Bu)Si.
When R1 and R2, together with the carbon atom bonding them, form 3- to 6-member ring, the ring includes cyclopropane ring, cyclobutane ring, cyclopentane ring or cyclohexane ring.
When R2 and R3, together with the allene bond group bonding them, form 8- to 10-member ring, the ring includes cyclooctane ring, cyclononane ring or cyclodecane ring.
The following is exemplified for each of the substituents in the chemical structural formula of the xcex2-diketonatocopper(I) complexes of formula (2).
The substituents R6 and R7 include, for example, CF3, C2F5, n-C3F7, i-C3F7, n-C4F9, Me, Et, n-Pr, n-Bu, i-Pr, i-Bu, s-Bu, t-Bu, MeO, EtO, n-PrO, n-BuO, i-PrO, i-BuO, s-BuO or t-BuO. In addition, the substituent R8 includes, for example H or F.
The present invention also relates to a process for producing a xcex2-diketonatocopper(I) complex represented by formula (2) 
wherein, R6 and R7 may be the same or different and each represents linear or branched C1-4 alkyl, C1-4 alkoxy, or linear or branched C1-4 fluoroalkyl, R8 represents hydrogen or fluorine, and L represents the allene compound of formula (1), characterized in that the process comprises reacting an allene compound of formula (1) 
wherein R1, R2, R3 and R4 may be the same or different and each represents hydrogen, C1-4 alkyl or (R5)3Sixe2x80x94, or R1 and R2, together with the carbon atom bonding them, may form 3- to 6-member ring, or R2 and R3, together with the allene bond group bonding them, may form 8- to 10-member ring, R5s may be the same or different and independently of one another represent linear or branched C1-4 alkyl, with an enol compound of formula (3) 
wherein R9 and R10 may be the same or different and each represents linear or branched C1-4 alkyl, C1-4 alkoxy, or linear or branched C1-4 fluoroalkyl, R11 represents hydrogen or fluorine in the presence of a copper(I) compound.
Next, the process for producing a xcex2-diketonatocopper(I) complex according to the present invention will be explained in more detail on the basis of reaction formulae (A) and (B). 
in formula (1) in reaction formula (A), R1, R2, R3 and R4 may be the same or different and each represents hydrogen, C1-4 alkyl or (R5)3Sixe2x80x94, or R1 and R2, together with the carbon atom bonding them, may form 3- to 6-member ring, or R2 and R3, together with the allene bond group bonding them, may form 8- to 10-member ring, R5s may be the same or different and independently of one another represent linear or branched C1-4 alkyl, in formula (3) or (4), R9 and R10 may be the same or different and each represents linear or branched C1-4 alkyl, C1-4 alkoxy, or linear or branched C1-4 fluoroalkyl, R11 represents hydrogen or fluorine, in formula (2), R6 and R7 may be the same or different and each represents linear or branched C1-4 alkyl, C1-4 alkoxy, or linear or branched C1-4 fluoroalkyl, R8 represents hydrogen or fluorine, and L represents the allene compound of formula (1).
In the reaction represented by reaction formula (A), a xcex2-diketonatocopper(I) complex in which an allene compound is coordinated can be synthesized by reacting an allene compound of formula (1) with an enol compound of formula (3) or a carbonyl compound of formula (4) (the compound of formula (4) is a tautomer of the compound of formula (3)) together with a copper(I) compound (CuX) of formula (5) optionally in the presence of a base (for example, inorganic base, such as sodium hydride, potassium hydride, sodium amide, potassium tertiary butoxide, potassium carbonate or the like).
The copper(I) compound includes, for example, Cu2O, CuF, CuCl, CuBr, Cul, CuOAc, CuCN, CuSCN, CuOTf and so on.
The enol compound of formula (3) is a tautomer of the carbonyl compound of formula (4) as indicated in reaction formula (B).
The molar ratio of the allene compound to the enol compound may be arbitrarily set. However, it is preferable that the enol compound and allene compound are mixed in an amount equimolar or close thereto. For example, the molar ratio of the enol compound to the allene compound may be 0.5 to 1.5.
The molar ratio of the allene compound to the copper(I) compound may be arbitrarily set. However, it is preferable that copper atoms in the copper(I) compound are equimolar with allene compound or that an excessive of the copper atoms is mixed with the allene compound. For example, the molar ratio of the copper atoms to the allene compound may be 0.5 to 3. The molar ratio of the base to the allene compound may be arbitrarily set. However, it is preferable that the base is equimolar with the allene compound or that an excessive of the base is mixed with the allene compound. For example, the molar ratio of the base to the allene compound may be 0.5 to 3.
Although the reaction temperature is not particularly limited, the reaction may be carried out generally at a temperature between xe2x88x92110xc2x0 C. and a boiling point of the solvent used in the reaction.
It is preferable to use solvents that do not participate in the reaction. The solvents that can be used include hydrocarbons (such as, hexane, pentane, benzene, toluene or the like), ethers (such as, diethyl ether, monoglyme, isopropyl ether, tetrahydrofuran, 1,4-dioxane or the like) and halogenated hydrocarbons (such as, dichloromethane, chloroform, dichloroethane or the like).
The xcex2-diketonatocopper(I) complex according to the present invention is useful as a compound for forming a thin copper film by MOCVD method.
The present invention will be concretely described on the basis of the following examples, but the present invention is not limited thereto at all.